DE No. 30 36 336 relates to a key operated switch with a key return spring of special design. This arrangement makes a particularly simple construction of a switch of flat design possible. Two tongues of this specially designed spring cause the resetting of the key shaft while a third tongue of the spring serves to close the contact. In copending U.S. application Ser. No. 811,437, filed December 20, 1985, a further development of an above mentioned switch is disclosed. Therein, conductors and switch contacts on a key carrier are designed as printed conductors; insulating coatings taking care that the conductors are insulated electrically. No insulation is present in certain places defining switch contacts to make contact closing possible.